#include<iostream>
#include<vector>
#include<algorithm>

int main() {
	int n;

	std::cin >> n;

	std::vector<int> v(n);

	for (int i = 0; i < n; i++) {
		std::cin >> v[i];
	}

	int count = 0;
	for (int i = n; i > 0; i--) {
		auto it = std::find(v.begin(), v.end(), i);
		if (it != v.end()) {
			auto tmp = it;
			it++;
			for (; it < v.end(); it++) {
				count++;
			}

			for (int j = 0; tmp != v.end(); j++) {
				tmp = v.erase(tmp);
			}
		}
	}

	std::cout << count << std::endl;
	return 0;
}